svelte/site/content/tutorial/12-actions/01-actions/app-b/App.svelte

<script>
	import { spring } from 'svelte/motion';
	import { pannable } from './pannable.js';

	const coords = spring({ x: 0, y: 0 }, {
		stiffness: 0.2,
		damping: 0.4
	});

	function handlePanStart() {
		coords.stiffness = coords.damping = 1;
	}

	function handlePanMove(event) {
		coords.update($coords => ({
			x: $coords.x + event.detail.dx,
			y: $coords.y + event.detail.dy
		}));
	}

	function handlePanEnd(event) {
		coords.stiffness = 0.2;
		coords.damping = 0.4;
		coords.set({ x: 0, y: 0 });
	}
</script>

<style>
	.box {
		--width: 100px;
		--height: 100px;
		position: absolute;
		width: var(--width);
		height: var(--height);
		left: calc(50% - var(--width) / 2);
		top: calc(50% - var(--height) / 2);
		border-radius: 4px;
		background-color: #ff3e00;
		cursor: move;
	}
</style>

<div class="box"
	use:pannable
	on:panstart={handlePanStart}
	on:panmove={handlePanMove}
	on:panend={handlePanEnd}
	style="transform: translate({$coords.x}px,{$coords.y}px)"
></div>